IRS-1A


IRS-1A, the first of the series of indigenous state-of-art remote sensing satellites, was successfully launched into a polar sun-synchronous orbit on 17 March 1988 from the Soviet Cosmodrome at Baikonur. IRS-1A carries three cameras, LISS-1, LISS-2A and LISS-2B with resolutions of and respectively with a swath width of about during each pass over the country. Undertaken by the Indian Space Research Organisation. It was a part-operational, part-experimental mission to develop Indian expertise in satellite imagery.

History

IRS-1A was the first remote sensing mission to provide imagery for various land-based applications, such as agriculture, forestry, geology, and hydrology. The mission's long-term objective was to develop indigenous remote sensing capability.

Spacecraft

The spacecraft platform, measuring 1.56 x 1.66 x 1.10 metres, had the payload module attached on the top and a deployable solar array stowed on either side. Attitude control was provided by four-momentum wheels, two magnetic torques, and a thruster system. Together, they gave an estimated accuracy of better than ± 0.10° in all three axes.

Payloads

IRS-1A carried three "Linear Imaging Self Scanner" cameras, LISS-1, LISS-2A and LISS-2B, with a spatial resolution of and respectively.
The three-axis-stabilised sun-synchronous satellite carried LISS cameras which performed "push-broom" scanning in visible and near-infrared bands to acquire images of the Earth. Local equatorial crossing time was fixed at around 10:30 of the morning.

Mission

IRS-1A was operated in a Sun-synchronous orbit. On 17 March 1988, it had a perigee of, an apogee of, an inclination of 99.01°, and an orbital period of 102.7 minutes.
IRS-1A successfully completed its mission in July 1996 after operating for 8 years and 4 months.